Results 1 to 9 of 9

Thread: Tyre Pressure

  1. #1
    Join Date
    Oct 2014
    Location
    Northern NSW.Australia
    Posts
    1,970
    Total Downloaded
    0

    Tyre Pressure

    Good Morning.
    Dropped Gilbert off to the local tyre shop.
    Just other side of road from where I work, and notice the LH Rear tube type tyre was low.
    Could have been a leaking valve, but didnt think of that until sitting for a coffee later in the morning, as I did a full check of oils and tyre pressures a week or two ago,
    And had trouble with a valve sealing.
    late finish so they kindly dropped it back to place of work, as they were closing.
    Well the drive home was S**t, felt every bump in the road, seem to over steer ??????
    Mmmmmm........
    This morning found the problem, which I had suspected. 40 to 46psi in the tyres.
    Back to 30psi now, so all back to normal.
    Did my own wheel alignment when first done, the two string lines and rotate tyres every 5.000 klms.
    Wearing nice and even, so will run at that pressure, even though the 'Experts' tell me its way to low.


    whitehillbilly

  2. #2
    Join Date
    Jun 2008
    Location
    The new Gold Coast, after ocean rises,Queensland
    Posts
    13,078
    Total Downloaded
    0
    I only go to a tyreshop to get new tyres or have a leak repaired.

    They always ask me what tyre pressures I like to run.

    the pressures touted here by some send shivers up my spine.

    understeer/oversteer......each to his own.....that is if you even understand the difference

  3. #3
    Join Date
    Jun 2013
    Location
    Universe A
    Posts
    2,076
    Total Downloaded
    0
    Quote Originally Posted by ramblingboy42 View Post
    I only go to a tyreshop to get new tyres or have a leak repaired.

    They always ask me what tyre pressures I like to run.

    the pressures touted here by some send shivers up my spine.

    understeer/oversteer......each to his own.....that is if you even understand the difference
    At the risk of starting a pressure war....

    What do you run?

  4. #4
    Join Date
    Apr 2019
    Location
    Koojan WA (part time Perth)
    Posts
    1,197
    Total Downloaded
    0
    Quote Originally Posted by shack View Post
    At the risk of starting a pressure war....

    What do you run?
    Whatever suits the vehicle/tyre brand/tyre size/load/terrain etc etc

    I’ve found over the years to try different pressures and keep an eye on the wear
    If the centre of the tread is wearing more than the outside, let some air out
    If the outside of the tread is wearing quicker than the centre, put some air in

    The side wall of the tyre gives you a good guide to what pressure to run compared to what load on the tyre
    1985 110 Dual Cab 4.6 R380 ARB Lockers (currently NIS due to roof kissing road)
    1985 110 Station Wagon 3.5 LT85 (unmolested blank canvas)

  5. #5
    Join Date
    Jun 2013
    Location
    Universe A
    Posts
    2,076
    Total Downloaded
    0
    That's essentially what we do as well, I guess one thing that always amazes me is when we are on a track up north from home...oodnadatta for instance, and everyone is "airing down" , I'm just looking at the rd thinking "it's better than the roads at home that we run standard pressures on every day".

    But that's probably just us!

    Cheers
    James

  6. #6
    Join Date
    Oct 2014
    Location
    Northern NSW.Australia
    Posts
    1,970
    Total Downloaded
    0
    'If the centre of the tread is wearing more than the outside, let some air out'
    I think this is why tyre manufactures suggest Fitters run higher pressures.
    After all they need to stay in Business.
    I have used the same tyre company for 30 years. Went in today to pay and Ask Laurie, who put the tyres ups to 40/46 psi.
    He just laughed, 'knew you would check them'........
    I keep check with a little depth gauge, middle and two outer edges. Then adjust a little if needed.
    And rotate correctly.
    Thanks for the comments.

    whitehillbilly

  7. #7
    Join Date
    Jul 2006
    Location
    Tumbi Umbi, Central Coast, NSW
    Posts
    5,743
    Total Downloaded
    0
    The 4psi rule works pretty well.

    1973 Series III LWB 1983 - 2006
    1998 300 Tdi Defender Trayback 2006 - often fitted with a Trayon slide-on camper.

  8. #8
    Join Date
    Jun 2013
    Location
    Universe A
    Posts
    2,076
    Total Downloaded
    0
    Quote Originally Posted by vnx205 View Post
    The 4psi rule works pretty well.
    I know the 4 psi rule, but after much consideration I'm wondering if it's flawed.
    We have been running TPMS for years, watching this, the difference in tyre pressure based on what side the sun is shining can be considerable.

    In controlled conditions it may work with some tyres, but in real world use it's really hard to even get a benchmark pressure/temperature reading.

    If ambient is 10° and overcast, does the "4 psi rule" have the same relevance as when I jump in the car just after fitting tyres and it's 40° and sunny.

    You can get 4 psi differential from side to side in tyres at 10 in the morning when you haven't even driven the car, and the sun is shining on one side. And the same issue on dirt roads vs bitumen.

    I may be wrong and I am happy to be corrected, but maybe that's why Michelin stopped recommending it?

    Cheers
    James

  9. #9
    JDNSW's Avatar
    JDNSW is offline RoverLord Silver Subscriber
    Join Date
    Jan 1970
    Location
    Central West NSW
    Posts
    28,804
    Total Downloaded
    0
    If we are talking about tyre pressures on Series vehicles, something worth considering.

    From the owner's handbook:- Series 2a 1964 Radial 20/20, 20/35 full load; Series 2a 1970 and same for 1981 Series 3 Radial 25/25, 25/36 full load: Both are same tyre and 7.50x16.

    What is the best tyre pressure depends on what you are trying to achieve.

    Tyre pressure affects tyre life, traction, handling, ride, fuel economy. Which one of these do you want to put at the top priority?

    Maximum tyre life requires a pressure that does not allow a significant temperature buildup. How important this is depends on how fast you are driving and the ambient temperature, but is often higher than optimum for other priorities.

    Best traction will require lower pressures than any of the other priorities, but usually this is only important on soft or loose surfaces such as sand or mud.

    Handling requires a high enough pressure for tyres to not flex enough to affect steering (or on some vehicles require flex to be adjusted between front and rear to have an effect that counters suspension or steering issues; not relevant for Series Landrovers). This is a key reason for changing rear (and to a lesser extent front) tyre pressures on Series Landrovers according to load.

    Best ride is invariably a lower pressure that all the other priorities except perhaps extreme traction requirements.

    Best fuel economy is invariably a ridiculously high pressure, which nobody would dream of except in

    My experience (7.50 radials, 2a 109) is that my "normal" pressures for everyday use is 25/25, increasing to 25/30 when well loaded. This is increased to 35/35 or 35/40 for long highway runs, and reduced to as low as 12/18 in very soft conditions.
    John

    JDNSW
    1986 110 County 3.9 diesel
    1970 2a 109 2.25 petrol

Tags for this Thread

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Search AULRO.com ONLY!
Search All the Web!